by Janice Lloyd, USA TODAY

by Janice Lloyd, USA TODAY

Veteran TV journalist Barbara Walters, hospitalized 10 days ago after a fall, turns out to have a rare adult case of chickenpox, her co-host Whoopi Goldberg said Monday on ABC's The View. Walters, 83, fell and hit her head at a party at the British ambassador's residence in Washington, D.C. She had had a persistent fever, which was later linked to chickenpox. Walters never had chickenpox as a child, Goldberg said. USA TODAY talks with David Nace, a physician in the geriatric division at the University of Pittsburgh Medical Center (not involved in Walters' care) about the illness in adults.

Q: How unusual is chickenpox in adults?A: Ninety percent of the people who get chickenpox get it before age 13. I have never seen a case in anyone over the age of 60. In medical literature, only a handful of cases are reported among people older than 60. When we were in training we'd come across a condition in the hospital and ask how common is this condition? The doctors would say you'll see references to it on the first part of the board exams, the second part of the boards and the third part of the boards. Chickenpox occurring in someone in their 80s doesn't even make the boards. That's how unusual it is.

Q: What causes chickenpox and can it be more severe in adults?A: The varicella-zoster virus causes chickenpox. Symptoms include a blister-type rash, itching, fever and fatigue. It can be more severe in infants and adults. We worry about pneumonia developing in adults because the virus appears to affect the lungs. Antivirals can help treat the pneumonia. There can be other complications in adults, like brain infections, but they're rare.

Q; How does chickenpox differ from shingles, which is an adults' disease?A: Once you are infected with varicella it remains in your body. Shingles is caused by a re-activation of the virus; it is characterized by a severe burning sensation and often appears as a rash on one part of the body. If you have never had chickenpox, avoid someone with shingles. It could be that Barbara was exposed to someone with shingles. As we get older the immune system tends to be less effective, but she's obviously very healthy otherwise.

Q: What's the best way to prevent chickenpox?A: Get the chickenpox vaccine when you're young. It wasn't made available until 1995, so that wasn't an option for her. Most people who get the vaccine do not get chickenpox, and if they do, it's mild. Adults who do not think they've had chickenpox can certainly talk to their physicians about getting the vaccine, but a doctor would first check to see if an adult has been exposed to the virus in the past. It could be they had a mild form. We assume anyone 50 plus has had chickenpox.

Q: Can an adult shingles vaccine protect someone who hasn't had chickenpox from getting chickenpox?A: The shingles vaccine might help prevent chickenpox in an older adult, but we don't really know. We assume that anyone older than 50 has had chickenpox. That's one reason why we recommend the shingles vaccine for anyone who is older than 60.